If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Chofu: The hottest months are usually August and July, with an average temperature of 25°C, while the coldest months are January and February, with an average of 7°C. The rainiest months in Chofu are September, October, July and June, with each month seeing an average of 209 mm of rainfall.